Project Summary All of us are taxed with juggling our inner mental lives and immediate external task demands. The temporary maintenance of task-relevant internal information in working memory is a vital cognitive function, but it is vulnerable to disruption by irrelevant perceptual input and competing attention demands. We lack a clear characterization, however, of the conditions under which distraction will be most disruptive, as well as a neurobiological explanation for how we successfully resist its impact. The current proposal uses converging neuroimaging and causal transcranial magnetic stimulation (TMS) methods, as well as advanced brain network connectivity analysis techniques, to shed light on the neural processes that promote and prevent distraction during working memory. The experiments employ a novel behavioral task that combines levels of distraction from two primary sources?perceptual interference and attention demand?to look at their unique and interacting effects on maintenance of information in working memory. Aim 1 measures the reconfiguration of functional connectivity patterns between brain networks that control and represent working memory information in response to distraction demands. Aim 2 manipulates neural activity with TMS to a) test the causal contribution of particular brain nodes to WM behavior and b) probe the distraction-dependent effects of that stimulation on activity and connectivity in interacting brain networks. The proposed cutting-edge data acquisition and analysis techniques represent novel strategies for addressing perplexing inconsistencies in our understanding of distraction effects, as well as invaluable fellowship training goals. The application of a non- invasive neurostimulation technique, in particular, will allow a precise and directional delineation of the neural components of distractor-resistant working memory, unachievable with common correlational (i.e., neuroimaging) techniques alone. The proposed studies will mark both a conceptual and methodological advance in understanding the persistence of working memory despite the interruptions and diversions that are so common in daily life.